#include <iostream>
#include <cmath>
#include <cstring>
using namespace std;
double ln(int n,double lold,double hold){
	if(n==6){
		return 1;
	}else{
		return sqrt((lold/2)*(lold/2)+(1-hold)*(1-hold));
	}
}
double hn(double lnew){
	return sqrt(1-(lnew/2)*(lnew/2));
}
int main(){
	int n=6;
	double lnew,lold,hnew,hold,pi;
	for(int i=1;i<=20;i++){
		lnew=ln(n,lold,hold);
		lold=lnew;
		hnew=hn(lnew);
		hold=hnew;
        pi=n*lnew/2;
        //cout<<n<<" "<<pi<<endl;
        printf("%d %10.9f \n",n,pi);
        n=2*n;
	}
	return 0;
}
